This read-only variable will return true if the
instance is classed as being a kinematic object, or false
if it is not. A kinematic instance is one that has infinite mass (a
density of 0) but can move. So, to make an instance kinematic, you
would first create a static instance and then set one or more of
the instance variables related to movement (ie: phy_speed_x).
phy_speed_x = 5;
The above code checks to see if the instance is kinematic and if it is not, it sets the horizontal speed to 5.